Pump sealing apparatus



June 16, 1964 3,137,237

l. F. ZAGAR ETAL PUMP SEALING APPARATUS Filed Aug. 22, 1961 4 Sheets-Sheet 1 :EIGL-l.

'77Go el B068 mvENToRs IEVlN F, ZAG-EZ 'o" GEoEGE M. UJlLFLEY BYQ Q NW6 um ATTORNEYSl June 16, 1964 l. F. ZAGAR ETAL 3,137,237

PUMP SEALING APPARATUS Filed Aug. 22, 1961 HO :E163 l 4 Sheets-Sheet 2 \4 lao l A o :Faas f :FIG-5 Morolz 26| ll |62 113 V14 no 26- J W 1/ y 25' k\/ Y |462 so 25' W. (gf/16, d

35' e2' .5o. 55 m l 1o' "o INVENTORS ATTORNEYS June 16, 1964 l. F. ZAGAR ETAL 3,137,237

PUMP SEALING APPARATUS Filed Aug. 22, 1961 4 Sheets-Sheet 3 ATTORNEYS June 16, 1964 l. F. ZAGAR ETAL r3,137,237

PUMP SEALING APPARATUS Filed Aug. 22, 1961 4 Sheets-Sheet 4 INVENTORS Ilzvm F. ZAGEIZ. Geom M.W\ Lv-LEY WMM@ ATTORNEYS United States Patent O 3,137,237 PUMP SEALING APPARATUS p Irvin F. Zagar and George M. Willey, both of Denver, Colo., assignors to A. R. Williey and Sous, Inc., Denver, Colo., a corporation of Colorado Filed Aug. 22', 1961, Ser. No. 133,167

. 16 Claims. (Cl. 10S- 87) Y The present invention relates to pump sealing apparatus, and more particularly to centrifugal pumps which are especially adaptedfor pumping Vcorrosive and abrasive materials.

The problem has; long existed in the art of centrifugal pumps ofproviding a satisfactory seal for the pump while it is operating. Due to the nature of the material being pumped, it is desirable to eliminate mechanical seals whichv would produce frictional contact during operation of the pump.

As a result of this problem existingin centrifugal pumps, arrangements have been employed which produce a socalled hydraulic seal when the pump is operating. This hydraulic seal may be provided Vin various ways, and may for example be provided byY employing expeller vanes on the impeller of the pump,` these expeller vanes tending to' evacuate any liquid which may leak past the impeller ,during operation."

'ice

. the sealing surfaces during rotation of the pump. With When employing such hydraulic seals, the impeller shaft y is normally shifted to a mechanically sealing position Y when the shaft Vis not rotating., and thenwhen the shaft reaches a predetermined speed, the entire impeller shaft is shifted axially` to break the mechanical seal and the hydraulic seal is relied upon during' operation. A typical example of this arrangement is illustrated 'in U.S. Patent Nol 2,571,802to Willley, et al., wherein the drive is transmitted to the impeller shaft through a resilient spring 'connection, and a centrifugal control means `is provided for shifting the impeller lshaft in anaxial direction at predetermined speeds of the shaft;

While such prior art arrangements have proved to be successful, it is' apparent thatthe special driving connections`V of the impeller shaft as well as the other structure for shifting the shaft and permitting' shifting of the shaft is rather complex in construction;v A particular feature of the present'invention is the elimination of the necessity of shifting the impeller shaft at` all, thereby substantially simplifying the over-all construction.

In the present invention, a flexible sealing means is employed which normallyprovides a good, mechanical seal'when the pump is not rotating. This is accomplished by providing means which normally urges the sealing meansinto sealing position when the various components of the'pump' are at rest.

In the most basic arrangementof the present invention, a flexible diaphragm is employed, the construction of the diaphragm itself being suchthat it normally assumes a sealing position. This iiexible diaphragm includes a sealing ysurface which cooperates'with -a sealing surface supported on the rotatable impeller'shaft.

' One side of the diaphragm isfsubjected to the pressures existing at theV impeller of vthe pump, while the other side of the'diaphragm is subjected to `atmospheric pressure through the exhaustmeans normally employed for allovv-` ing any iluid which leaks past theimpeller to be vented from the pump.

The pressureacting onY the impeller side of the diabe maintained in sealing position.Y

On the other hand, the pressurele'xisting on the impeller side yof thev diaphragm is normally less than atmospheric' Y means for the sealing meansgand when the pump is operated, `and accordingly the dia- Aphragmgwill be urged in such a direction asto separate` means for the sealing means; t

this arrangement, a very effective seal is obtained when the pump is at rest and the sealing surfaces are separated from one another when the pump is rotating, and at the same time very little liquid will leak past the seal during the time it is not in sealing position.

As described above, the sealing means .may be automatically operated by the pressures acting on the opposite sides thereof, but in certain instances where the sealing means may be of great thickness or where it is made of a material which is not very flexible, or where the operation is under severe pumping conditions, an auxiliary shifting means may be employed. This auxiliary shifting means may assume various forms as hereinafter described, but in each case, the auxiliary shifting means will be interrelated with the rotation of the impeller shaft such that the sealing means Will be in operative sealing position whenthe impeller shaft is at rest, and thesealing means will be automatically shifted to open position upon pre-determined rotation of the impeller shaft.

An objectof the present invention is to provide new and novel pump sealing apparatus which provides an effective mechanical seal when the pump is not operating, and yet which eliminates any frictional contact between .the mechanical sealing members when the pumpiis operatmg.

Another object of the invention is the provision of pump sealing apparatus wherein the mechanically sealing portions of the sealing means are automatically separated from one another Vupon actuation of the pump.

A further object of the invention is to provide auxiliary shifting means for shifting the sealing means in accordance with pre-determined rotation of the impeller shaft of the pump.

A still further object of the invention is to provide pump sealing apparatuswhich completely eliminates `any shifting of the impeller shaft for obtaining the desired end results. n Y

Yet another object of the invention is the provision of pump sealing apparatus which is quite simple and inexpensive in construction and yet able in operation.

Other objects and many attendant advantages Yof the invention wil-l become more apparent when considered in connection with the specification and accompanying drawings, wherein: l

FIG. 1 is a longitudinal section through a portion of a centrifugal pump illustrating the basic sealing arrangement of the present invention; Y

FIG. 2 isan enlarged'view of a portion of thel structure shownin FIG. l illustrating the mechanical sealing members separated from one another; t.

FIG. V3 is Va sectional view illustrating an auxiliary actuating means for the sealing means;

FIG. 4 illustrates a further modified form of actuating means for the sealing means; g i t FIG.r 5Y illustrates afurther modified form of actuating means for the sealing means;

which is efficient and reli IG. 'illustrates a further modified formV of actuating means for the sealing means;

' FIG. 7 illustrates a further modified `form `of actuating FIG. .8`illustrates a further modified form of actuating FIG. 9 is a longitudinal section illustrating'a slightly modified form of the'sealingY means along with a still further modified type of actuator means for the sealing means. f

Referring now to the drawings wherein like reference charactersdesignate corresponding parts throughout theL several views, there is shown paiticularlyrin FIGS. l and"V 2 theover-all pump housing which is indicated generally by reference numeral 10, this housing consisting of several assemblies which are interconnected with one another to provide the complete assembly for enclosing the various components of the pumping apparatus. The housing includesv a base portion 11 including upwardly extending supporting portions 12 and 13 for supporting varlous portions of the apparatus.

A tubular member 15 supports a ball bearing 17 havlng balls 18, an inner race 19, and an outer race 20. This rollerV bearing serves to journal a portion of the impeller shaft 25, the ball bearing being held in place between a shoulder 27 on the impeller shaft and a portion of a collector housing 26. p

' The impeller shaft is drivingly connected to a suitable pump motor in the conventional manner, and a reduced portion 28 of the impeller shaft is also journaled within a ball bearing 30 mounted within a portion 31 of the collector housing 26.

' The terminal end portion 34 of the impeller shaft is threaded, and an impeller indicated generally by reference numeral 35 is threaded on the outer end 34 of the impeller shaft in a well-known manner. The impeller includes a plurality of conventional pump vanes 37, as Well as a plurality of conventional expeller vanes 38, these expeller vane'sbeing employed for the purpose of producing a hydraulic selal in a well-known manner.

The impeller housing is indicated generally by reference numeral 40, and a circumferential laterally extending flange 42 extends forwardly of the impeller and tits within and is spaced from the walls of a groove 43 formed in the impeller housing thereby providing a labyrinth means therewith. In a like manner, a circumferential laterally extending flange 45 extends rearwardly of the impeller and lits within and is spaced from the walls of a groove 46 formed in the impeller housing for providing a labyrinth means therewith.

Fluid entering through the inlet bore 50 of the impeller housing is pumped outwardly by pump vanes 37 and then moves out of the pumping apparatus through the discharge outlet 51.

Expeller vanes 38 will also tend to pump out any fluid whichmay leak by the labyrinth means dened by flange 45 and groove 46, thereby tending to prevent any liquid from passing toward the rear of the apparatus while the impeller is rotating during its pumping action.

The impeller housing includes a relieved portion 55 and anfannular spaceV 56 is provided between the impeller housing and the outer portion of the impeller itself. This permits fluid which may leak by the labyrinth defined by flange 45 and groove 46 to pass into a space indicated by letter A. This space A is defined between the impeller housing and a portion of the sealing means generally indicated by reference numeral 60.

Another space B is defined between the sealing means 60 and a portion of the collector housing 26 as well as a portion of a shaft sleeve 62 which is affixed to the impeller shaft.

Shaft sleeve 62 has a pair of annular grooves 65 and 66`formed in the outer surface thereof, and collector housing 26 has a corresponding pair of annular grooves 68 and 69 formed in the inner surface thereof, it being notedy thatgrooves 68 and 69 are axially aligned with grooves 65 and 66 respectively. K y

An exhaust outlet 70 is provided through the collector housing-26, and it will be noted that any fluid within the space B will pass throughthe clearance space between the' shaft sleeve 62 and collector housing 26, and thence through the cooperating annular grooves 65-69 and outwardly through the exhaust outlet means 70. vIn this manner, anyexeess fluid which leaks past the hydraulic seal provided by the expeller vanes of the impeller Will be directedharmlesslyout of the pump apparatus.; Sealing means 60 in this example comprisesa diaphragm formed of flexible material and may be formed of "various materials such as rubber, Teflon, polyethylene, and in some cases may take the form of a flexible metallic bellows. As shown, the diaphragm is illustrated as formed of a plastic material such as Teflon which has good corrosion and abrasion resistant qualities and further which is suiciently flexible to permit the desired movement thereof during operation.

A desirable feature of a plastic sealing means is the fact that it may have a so-called molded memory built into it whereby it will tend to assume the position shown in FIG. 1 to provide a seal, and it will return to this position Whenever the pressures on opposite sides thereof do not force it away from the position shown.

A first edge portion 75 of the sealing means is clamped to the impeller housing by means of an annular clamping ring 76 bolted to the impeller housing by a plurality of spaced bolts 77.

In a like manner, the opposite edge portions 80 of the sealing means is fxedly clamped to the collector housing 26 by an annular clamping ring 81 held in place by a plurality of spaced bolts 82. It is accordingly evident that the opposite edge portions of the flexible diaphragm comprising the sealing means are rigidly secured to fixed members. The intermediate portion 85 of the diaphragm is substantially U-shaped in cross-sectional configuration, and an annular laterally extending flange portion 86 extends rearwardly therefrom, the outer face of flange portion 86 defining a flat sealing surface.

The liat sealing surface formed on flange portion 86 of the sealing means is adapted to engage a cooperating flat sealing surface supported on shaft sleeve 62. In the present example, an insert 87 is shown as supported on shaft sleeve 62, this insert being formed of a suitable corrosion and abrasion resistant material such as Teon or the like and defining a flat sealing surface which is adapted to engage flush with the at sealing surface on the diaphragm.

As shown in in FIG. 1, the sealing means is in operative sealing position, and the pump is at rest. In this position, the uid head of the pump will exist in space A, this fluid head normally being substantially greater than atmospheric pressure, which exists in space B, due to its communication with atmosphere through the exhaust outlet means 70. It is therefore clear that a 'greater pressure exists on the impeller side of the diaphragm than on the exhaust outlet side of the diaphragm, and accordingly, the diaphragm will be urged into its closed sealing position by the pressures acting thereon as well as the natural tendency of the diaphragm itself to assume this sealing position.

-Upon actuation of the pump and rotation of the impeller shaft, the pumping and expeller vanes operate on the fluid within the pump and the pressure within space A will drop below atmospheric pressure whereupon the atmospheric pressure existing in space B will move the diaphragm sealing means into the open position shown in FIG. 2.

The diaphragm will be retained in the position shown in FIG. 2 during operation of the pump since the pressures acting on opposite sides of the diaphragm will keep the diaphragm in such position. As indicated by the ,arrows in FIG. 2, any liquid which may kleak past the hydraulic seal will be vented from the pump.` through the exhaustoutlet means 70. It is of course evident that the sealing surfaces provided on will be moved back toits sealing position as uid again enters space A and increases the pressure therein to a point greater thany atmospheric pressure.

The diaphragm will be moved to its openposition as soon as the pump is up to speed which is a matter of seconds, and accordingly, there is not any appreciable rubbing contact between the sealing surfaces upon starting of the pump.

Additionally, when the pump is stopped, and the diaphragm is moved back into sealing contact, there is very little rubbing contact between the sealing surfaces since the time involved for the pump to stop after the power is cut off is very short.` i

Since the collector housing 26 and the shaft sleeve 62 will be in some slight contact with the pumped solution, these components are preferably formed of an abrasion and` corrosion resistant material. The sealing faces of the apparatus are preferably of a suitable material to withstand the slight frictional contact which occurs during operation, and these sealing surfaces may be formed for example of rubber with fiber or fabric, metallic material, ceramic material or plastic material.

Referring now to FIG. 3 of the drawings, a modificationis illustrated wherein a solenoid auxiliary actuator is employed for assisting the movement of the diaphragm sealing means.V The components of FIG. 3 which are similar to those shown in FIG. 1 have been given the same reference numerals primed.

In this modification, the diaphragm sealing means 100 is of similar configuration to the diaphragm sealing Vmeans 60 previously discussed, `and is held in place by retaining rings 101 and 102 bolted to the impeller housing'and collector housing respectively.

An annular plate member 105 has the inner portion 106 thereof seated within the intermediate portion of the diaphragm and fitted snugly therewithin. The outer portion of plate 105 is connected with one or more solenoids 103, solenoid 108 as seen in FIG. 3 being mounted upon the impeller housing and including a plunger 110 which is operatively connected with plate 105.

Plate y105 is also connected by one or more spring members V112- to the-clamping ring 102 attached to the collector housing 26.

The spring 112 is adapted to continuously resiliently urge the plate 105 as seen in FIG. 3 to the right thereby causing the diaphragm to be sealingly seated against the ycooperating sealing surface formed on shaft sleeve 62'.

Solenoid 108 is4 electrically connected through a lead 114 to a timing device 115 which is in turn electrically ,y connected with the motor which drives the impeller shaft. y

l When the main pump switch is closed, the circuit is closed through the timing device 115, and a suitable time vdelay occurs before the solenoid 108 is actuatedto open the sealing means. f

When the pump motor is shut off, the solenoid 108 will be de-energized after a suitable time delay where- Vupon spring 112 will move the sealing diaphragm into Referringv now to FIG. 4,' afurther modified auxiliary actuating means is illustrated'and again in thismodification theY components similar to those discussedin connection with FIG. 1 have been given the same reference numeralprimed. In this modification, the seaiingdiaphragm is retained inposition by lannular sealing ringsl 121 and 122 as previously described. An annular Vplate member 125 formedof magnetic material such as iron or the like Vis snugly received within the intermediate portion of the diaphragm,- `and it will be noted that a laterally extending annular portion 126 at the inner portion` thereof isreceived within a hollow portion of the laterally extending flange 127 of the diaphragm.

` A circumferential laterally extending portion 128- is formed on the outer portion of the plate 12S and extends in a direction opposite to the flange portion 126. Flange portion 128 forms themovable core of an electro-magnet indicated by reference numeral 130, the electro-magnet being electrically connected with the driving motor of the pump.

A permanent magnet 132 is supported on the shaft sleeve 62', permanent magnet 132 being annular in configuration and normally attracting the portion 126 of plate 125 so as to urge the sealing surfaces into contact with one another. Y

When the main pump motor is started, the circuit is closed to the electro-magnet 130 which attracts the plate 125 to the left as seen in FIG. 4 thereby opening the sealing means. When the pump motor is shutoff, the electromagnet is de-energized and the permanent magnet 132 urges the plate 125 back to the right as seen in FIG. 4 to cause the sealing surfaces to again be urged into sealing contact with one another.

Referring now to FIG. 5, a further modified actuatingl means is illustrated, wherein the components similar to those of FIG. l have again been given the same reference numerals primed. Here again,'the flexible sealing diaphragm is retained inposition by a pair of clamping rings 141 and 142. An electro-magnet device 145 is snugly fitted within the central portion of diaphragm 140, and it will be noted that a laterally extending portion 146 of the electro-magnet device extends within a hollowed portion of the laterally extending flange 147 of the diaphragm. The electro-magnet device is electrically connected with the driving motor of the pump.

An annular permanent magnet 150 is supported on the shaft sleeve 62 and is in such a position that it will normally attract the magnetic material of the electro- Y magnet device 145 to cause the sealing surfaces to be urged into sealing contact with one another.

When the main pump motoris started, electro-.magnet device 145 is energized and its polarity is such that it is the same as the permanent magnet 150 thereby'causing a repellent force to occur and thereby separating the Ysealing faces.

When the main pump motor is switched off, the electromagnet device 145 is de-energized and theV permanent magnet 150 will cause the sealing faces to be again urged into contact with one another. Y- p Referring now to FIG. V6, a still further modied form 0f actuating means is provided where the parts corresponding to those of FIG. l are again provided with the same reference numerals primed.

In this modification, the iiexible sealing diaphragm is again retained in position by means of a pair of clamping rings l161 and 162. An annular permanent magnet 165 is snugly fitted within the central portion of diaphragm 160, and an electro-magnetic device 167 isl mounted upon the shaft-sleeve 62'. Electro-magnetic device 167 is connected through slip` rings 170 and 171 to brushes 173 and 174 which are in turn connected through a timing device 175 to the driving motor of the pump. l y When the pump motor is started, after a suitable time delay the electro-magnetic device 167 is energized so` that the polarity thereof is the same as the permanent magnet 165 and repels` the permanent magnet, causing the sealing faces to separate. An electro-magnet 177 is also illusf trated as supported within the flexible diaphragmy 160, it being apparent that this electro-magnet could also be energized with a polarity they same as that of electromagnetic device 167` to causerthe sealing faces Ato beseparated from one' another. When the main pump motor is stopped after a suitable time delay, the electro-magnetic device 167 is de-energized and the permanent magnet165 will cause the sealing diaphragm 1160 to. moveto the right to again close the sealing surfaces". f p Referring now to FIG. 7 of the drawings, a further modified form of actuating means is illustrated, and again parts similar to those shown in FIG. i l have been given the same reference numerals primed. It will be seen that the rear end portion of the impeller shaft 25 is journaled within a rear bearing 200 disposed within tubular member and a pulley 201 is xed to and rotates with the impeller shaft.

A flexible diaphragm seal 204 is retained in position by a pair of clamping rings 205 and 206 and a plate member 208 is snugly tted within the central portion of the ilexible diaphragm. This plate 208 is in turn connected with one or more piston rods 210, the piston rod 210 extending within a hydraulic cylinder 211, the piston rod having a head 212 at the terminal end thereof. A resilient spring 213 is seated against piston head 212 and normally urges the piston head to the right as seen in FIG. 7, thereby causing the flexible diaphragm 204 to be normally seated in sealing relationship.

A hydraulic pump 215 is driven through a shaft 216 having a pulley 217 connected to the outer end thereof, pulley 217 being drivingly connected with pulley 201 on the impeller shaft through a drive belt 218.

A conduit 220 connects the hydraulic pump with a two-way control valve 221, this valve being suitably electrically or pressure controlled so as to be actuated in accordance with the actuation of the pump motor and impeller shaft. Conduit means 222 connects the control valve with the interior of hydraulic cylinder 211 at the side of the piston head 212 opposite to the side on which the spring bears. A conduit means 224 connects valve 221 with a-reservoir 225 which in turn is connected through conduit means 226 to the hydraulic pump.

In operation, when the pump is started, the hydraulic pump 215 will be driven along with the impeller shaft. The control valve 221 is regulated to open after the eX- peller vanes of the main pump have reached a speed so that there is substantially no liquid on the impeller side of the sealing means which could leak past the sealing surfaces. Y

The control valve is then opened, and hydraulic pressure is applied through conduit 222 to the cylinder 213 forcing the piston within the cylinder to the left as seen in FIG. 7 and moving the sealing surfaces away from one another.

When the main pump motor is shut off, the hydraulic pump speed will decrease and hydraulic pressure starts to diminish. To speed up the closing of the sealing means, the control valve is then shifted to a position such that the cylinder 213 discharges through conduit 224 into the reservoir 225.

The spring 213 then rapidly moves plate 208 and the diaphragm to the right as seen in FIG. 7 to bring the sealing surfaces into contact with one another.

Referring now to FIG. 8, a pneumatic actuating system is illustrated which in many respects is quite similar to the hydraulic system shown in FIG. 7. Here again, portions similar to parts shown in FIG. l are given the same reference numerals primed. 1 n

In this modification, the diaphragm 204 is identical to the diaphragm 204 shown in FIG. 7, and the plate means 208 as well as the cylinder actuating means 211' are identical with the corresponding components 208 and 211 shown in FIG. 7. The principal distinction of the structure shownin FIG. 8 is the fact that air pressure may be utilized rather than hydraulic pressure.

An air compressor 230 is driven through a pulley 231 which is drivingly connected by belt 232 with a pulley 233 fixed for rotation with the 'impellershaft Air compressor 230 is connected through conduit 235 to an air storage tank v236 which is in turn connected with a conduit 237 which may be connected with a control valve 240. The control valve is connected through conduit 241 to the cylinder 211'.

A conduit 243 may be connected with any external source of air pressure or may be connected with conduit 237 as desired. A conduit 245 has an open end 246 which forms arventvto atmosphere.

With this arrange-n mentjthe operation is similar to that of the hydraulic system shown in FIG. 7. When the pump motor is started, control valve 240 is actuated after a suitable time delay to admit air pressure to cylinder 211? which moves the sealing surfaces out of contact with one another. When the pump is turned off, control valve 240 is shifted to connect conduit 241 to conduit 245 to vent the cylinder 211 to atmosphere whereupon the spring means within the cylinder urges the plate 208' to the right and causes the sealing surfaces to once again come into contact with one another.

Referring now to FIG. 9, a still further modified form of the invention is illustrated, wherein an impeller shaft 250 has an impeller 251 threaded on the outer end thereof, the impeller including pump vanes 252 and expeller vanes 253. A housing for the pump is illustrated generally by reference numeral 255.

A shaft sleeve 260 is mounted upon the impeller shaft and a collector housing 261 is bolted to the main pump housing. The shaft sleeve includes an annular groove 263 formed on the outer surface thereof and collector housing 261 includes a pair of annular grooves 264 and 265 formedon the inner surface thereof. The grooves 263, 264 and 265 conduct liquid to the exhaust outlet 268 which serves to carry liquid away from the pump as aforedescribed.

The sealing means in this example is illustrated by reference numeral 270 and may comprise a flexible metallic bellows member, the opposite ends of the metallic bellows being rigidly clamped in position by retainer rings 272 and 273`which are bolted to various portions of the main pump housing. p

A first sealing surface is formed by the rounded outer portion of a seal insert 275 which is mounted within the shaft sleeve 260, insert 275 being formed of a suitable plastic material or the like. An annular member 277 of substantially J-shaped cross-sectional configuration is affixed tothe inner surface of the central portion of the metallic bellows 270 and forms a flat sealing surface 278 which is adapted to engage the insert 275.

An annular plate 280 is snugly fitted within the intermediate portion of the bellows 270 and is connected with one or more push rods 281. Push rod 281 extends through suitable openings in the pump housing and collector housing members, and the outer end of the push rod is connected through clamping members 282 and 283 to a thrust bearing 284, the inner race of which is mounted on a shiftable sleeve 285. The inner race is held imposition by'a member 286, and 'a resilient spring 288 bears against member 286 for normally urging the bearing and sleeve to the right as seen in FIG. 9.

Sleeve 285 includes a radially extending ilange 290. A plurality of speedcontrolmembers 292 are pivotally mounted about axes 293 on members 294 which are fixed to the impeller shaft. Y

Weights 295 are formedat one end of the members 292 and cam surfaces 297 are formed at the opposite ends thereof. A

When the kpump motor is started and the impeller st laftpstartsV to rotate, the control members 292 will be pivoted Vabout the axes thereof asthe Weight portions 295 swing outward, this action causing the cam portions 297 to engage flange 290 of sleeve 285 thereby urging the sleeve to the left against the force of spring 288 as seen in FIG. 9. This motion will be transmitted through push rod 281 to plate 280 thereby moving the seal member 277away from seal member 275. When the pump is stopped, the impeller shaft will slow down and spring 288 will then overcome the force of the weight members and the sleeve 285 will again be urged to the right, such motion being transmitted through push rod 281 to the plate member 281 and the flexible bellows 270 Whereuponthesealing surfaces are again brought into contact with one another. Y- V A It is apparent from the foregoing that there is provided new and novel pump sealing apparatus which provides an effective mechanical seal when the pump is not rotating and yet which eliminates any frictional contact between the mechanical sealing members when the pump is operating.

The mechanical sealing portions are automatically separated upon actuation of the pump, and in some instances, an. auxiliary shifting means is provided for assisting in the opening and closing of the sealing means. The arrangement of the present invention completely eliminates the necessity of shifting the impeller shaft as has been done in prior art. The apparatus is quite simple and inexpensive in.. construction and yet is quite efficient and reliable in operation.

As this invention may be-embodied inseveral forms without departing from the spirit or essential characteristics thereof, the present embodiment is therefore illustrative andnot restrictive, and since the scope of the invention is defined by the appended claims, all changes that fall within the metes and bounds of the claims or that form their functional as well as conjointly cooperative equivalents are therefore intended to be embraced by those claims.

We claim:

1. Pump sealing apparatus comprising a pump having a rotatable means including an impeller, exhaust means in communication with atmosphere, and sealing means for preventing liquid flow between said impeller and .Said exhaudt means, said sealing meansv including a flexible movable intermediate portion, means normally retaining said sealing means in operative sealing position with said intermediate portion' in engagement wth a part of said rotatable means, and said pump including means for reducing pressure on the impeller side of the sealing means below the pressure on the other side of the sealing means to move said sealing means completely out of engagement with said rotatable means.

2. Pump sealing apparatus including a rotatable'impeller and exhaust means spaced from said impeller and in communication with atmosphere for venting liquid l from saidv impeller during certain `phases of operation of the pump, and sealing means having certain spaced portions thereof mounted in fixed relationship relative to the pump and including a free intermediate portion for engaging a rotatable portion of the pump intermediate said impeller andsaid exhaust means, said intermediate portion of the sealing means being flexible and freely movable, means for retaining the intermediate portion of the sealing means 'in sealing relationship relative to the cooperating portion of the pump, and means for reducing the pressure on the impeller side of the sealing means below atmospheric pressure to move said intermediate portion completely out of. sealing relationship relative tothe cooperating portion of the pump.

'g 3. Pump sealing apparatus including an impeller having pump vanes and expellerv vanes, said expeller vanes p being adapted to produce a 'hydraulic seal during rotation of the pump, said pump including exhaust meansin communication with atmosphere for exhausting liquid from the pump, said exhaust means being spaced from said expeller vanes, said pump including a sealing sur- Vface intermediatesaid expeller vanes and said exhaust means, sealing means including opposite end portions fixed relative to said pump and including a free flexible intermediate" portion forengaging said sealing surface,l

and means normally urgingsaid intermediate portion of the sealing means into engagement with.A said sealing surface, said'expell'er vanes reducing the pressure on the impeller side of the sealing meansl during operation to move the intermediate portion'fof the sealing means coinpletely out of engagement with said sealing surface,

Y 4. Apparatus as defined in claiml 3, wherein said sealing means comprises a diaphragm formed o'f corrosion and abrasion resistant material.

5. Pump sealing apparatus' comprising a` pump vincluding a'pump housing, an impeller shaft rotatably supportedV within said housing, an impeller mounted on said impeller shaft and including pump vanes and expeller vanes, said expeller vanes producing a hydraulic seal during rotation of the impeller shaft, a sleeve secured to said shaft and including a sealing surface thereon, a'sealing means comprising a flexible diaphragm means fixed with respect to said pump, said sealing means including a sealing surface formed on an intermediate portion thereof and engaging said first-mentioned sealing surface, means normally retaining said two sealing surfaces in contact with one another, said pump including exhaust means in communication with atmosphere for venting liquid from the pump, said exhaust means being in communication with one side of said sealing means, theV opposite side of said sealing means being in communication with said expeller vanes, whereby upon rotation of the pump the expeller vanes reduce the pressure below atmospheric pressure on said other side of the sealing means causing the intermediate portion of the sealing means to be moved to cause the sealing surfaces toy move away from one another.

6. Pump sealing apparatus including a pump housing, V

' from said first sealing surface mounted on said sleeve,

saidv operating means including at least one rod member movable longitudinally of said impeller shaft, and means for moving said last-mentioned member, resilient means normally urging said rod member in one direction so as to urge said sealing surfaces into engagement with one another, and means for moving said rod member in the opposite direction, said last-mentioned means being connected to and responsive to rotation of said impeller shaft for moving said sealing surfaces away from one another.

7. Pump sealing apparatus comprising a pump housing and an impeller shaft rotatably supported in said pump housing, an impeller mounted at one end of said impeller shaft, exhaust means in communication withv atmosphere for'venting the pump, a sleeve affixed to said impeller shaft and having a first sealing surface formed thereon, flexible sealing means having a second sealing surface formed `thereon for engagingV said first sealing surface, and actuating means connected with an intermediate'portion of said flexible sealing means, said actuating means including a fixed hydraulic cylinder, a piston slidably mounted within said cylinder and operatively connected with the intermediate portion of said sealing means, resilient means engaging said piston and urging said resilient sealing meanslin a direction to cause engagement of said first and second sealing surfaces, a source of hydraulic pressure, conduit means providingr communication between sa'id source of hydraulic pressure and said cylinder, and a control valve means connected in said conduit means for controlling the flow of hydraulic fluidto said cylinder. v i i 8. Pump sealing apparatuscomprising. a pump housing and` an impeller shaft rotatably supportedin said pump housing, an impeller mounted at one end of said impeller shaft, exhaust means in communication with atmosphere for venting the pump, a sleeve afiixed to said impeller shaftand having a first sealingsurface formed thereon, flexible sealing means'having a second sealing surface formedl thereon for engagingV said first sealing surface, and actuating means connected with an intermediate portionof said flexible sealing means, said actuating means including a fixed uid cylinder, a piston slidably mounted within said cylinder and opveratively connected with the intermediate portion of said sealing means, resilient means engaging said piston and urging said resilient sealing means in a direction to cause engagement of said first and second sealing surfaces, a source of fiuid pressure, conduit means connecting said source of pressure to said cylinder, control valve means connected in said conduit means, and vent conduit means in communication with atmosphere connected with said control valve means, whereby said cylinder may be connected either with said source of pressure or with atmosphere.

'9. Pump sealing' apparatus including a pump housing, an impeller shaft rotatably supported within said housing, an impeller operatively connected with said impeller shaft, exhaust means in communication with atmosphere for venting the pump, a sleeve affixed to said impeller shaft and supporting a first sealing surface, a sealing means comprising a flexible body having a second sealing surface supported thereon, and operating means for moving said second sealing surface toward and away from said first sealing surface mounted on said sleeve, said operating means including a solenoid operatively connected with said sealing means, a motor for driving said impeller shaft, said solenoid being electrically connected with said motor through a timing device so that when the motor is actuated the solenoid will be energized to move said second sealing surface away from said first sealing surface after a suitable time delay, and resilient means connected with said sealing means normally urging said second sealing surface toward said first sealing surface.

10. Pump sealing apparatus including a pump housing, an impeller shaft rotatably supported within said housing, an impeller operatively connected with said impeller shaft, exhaust means in communication with atmosphere for venting the pump, a sleeve afiixed to said impeller shaft and supporting a first sealing surface, a sealing means comprising a fiexible body having a second sealing surface supported thereon, and operating means for moving said second sealing surface toward and away from said first sealing surface mounted on said sleeve, said operating means comprising a plate member operatively connected with an intermediate portion of said sealing means and being formed of magnetic material, a permanent magnet means mounted on said sleeve normally attracting said plate toward said sleeve to cause engagement of said first and second sealing surfaces, and electro-magnet means operatively associated with said plate means, a motor for driving'said impeller shaft, said electro-magnet means being electrically connected with said motor such that when the motor is actuated the electro-magnet is energized and will urge said plate means in a direction to move said second sealing surface away from said first sealing surface.

l1. Pump sealing apparatus including a pump housing, an impeller shaft rotatably supported within said housing, an impeller operatively connected with said impeller shaft, exhaust means in communication with atmosphere for venting the pump, a sleeve affixed to said impeller shaft and supporting a first sealing surface, a sealing means comprising a fiexible body having a second sealing surface supported thereon, and operating means for moving said second sealing surface toward and away from said first sealing surface mountedonsaid sleeve, said oper-` ating means comprising an electro-magnetic means operatively connected with an intermediateA portion of said sealing means, a permanent magnet supported by said sleeve, a motor drivingly connected to said impeller shaft, said electro-magnetic means being electrically connected to said motor so that when the motor is actuated, the electro-magnetic means is energized, the polarity of the electro-magnetic means being the same as that of the permanent magnet causing a repellingvforce to be produced urging said second sealing surface away from said first sealing surface, the permanent magnet serving to attract the second sealing surface toward the first sealing surface when the electro-magnetic device is de-energized.

' 12. Pump sealing apparatus including a pump housing, an impeller shaft rotatably supported within said housing, an impeller operatively connected with said impeller shaft, exhaust means in communication with atmosphere for venting the pump, a sleeve affixed to said impeller shaft and supporting a first sealing surface, a sealing means comprising a fiexible body having a second sealing surface supported thereon, and operating means for -moving said second sealing surface toward and away from said first sealing surface mounted on said sleeve, said operating means comprising a permanent magnet means operatively connected with an intermediate .portion of said sealing means, and an electro-magnetic means supported on said sleeve, a motor drivingly connected with said impeller shaft, said electro-magnetic device being connected to said motor through a timing device, brushes and slip rings so that when the motor is actuated the electro-magnetic device is energized, the polarity of the electro-magnetic device being the same as the permanent magnet to produce a repelling force urging said second sealing surface away from said first sealing surface, the permanent magnet serving to attract said second sealing surface toward said first sealing surface when the electro-magnetic device is deenergized.

13. Pump sealing apparatus comprising a pump including a pump housing, an impeller shaft rotatably supported within said pump housing, an impeller at the end portion of said impeller shaft, means supported on said impeller shaft defining a first annular sealing surface, said pump including exhaust means in communication with atmosphere, said annular sealing surface being disposed between said impeller and said exhaust means, and sealing means comprising a generally annularly extending flexible diaphragm, the opposite edge portions of said diaphragm being clamped in fixed position, the intermediate portion of said diaphragm being free and defining a second annular sealing surface adapted to engage said first annular sealing surface, and means normally urging said second sealing surface into engagement with said first sealing surface, and means for reducing the pressure on the impeller side of the sealing means below atmospheric pressure to move said second annular sealing surface completely out of engagement with said first annular sealing surface.

14. Sealing means for use in sealing a pump comprising a generally annularly extending diaphragm formed of flexible material, the opposite edges of said diaphragm being adapted to be clamped in fixed relationship, the intermediate portion of said diaphragm being unperforated and continuous to prevent liquid flow therethrough and being substantially U-shaped in cross-sectional configuration and an annular laterally extending ange portion formed on said intermediate portion and defining an annular sealing surface adapted to engage acooperating annular sealing surface formed on a pump.

15. Pump sealing apparatus comprising a pump including a pump housing, an impeller shaft rotatably supported withinsaid housing, an impeller mounted on said impeller shaft and including pump vanes and expeller vanes, said expeller vanes producing a hydraulic seal during rotation of the impeller shaft, a sleeve secured to said shaft and including a sealing sur/face thereon, a'sealing means comprising a flexible diaphragm means fixed with respect to said pump, said sealing means including a sealing surface formed on an intermediate portion thereof and engaging saidrfirst-mentioned sealing surface, means normally retaining said two sealing surfaces in contact with one another, said pump includingn exhaust means in communication with atmosphere for venting liquid from the pump, said exhaust means being vin communication with one side of'saidrsealing means, the opposite side of said sealing meansbeing in communication with said expeller vanes, whereby upon rotation of Ithe pump the expeller vanes reduce the pressure below atmospheric pressure on said other side of the sealing means causing the intermediate portion of the sealing means to be moved to cause the sealing surfaces to move aWay from one another, the opposite edge portions of said diaphragm means being clamped 5 in xed position, said intermediate portion of the dia- 1,085,326 phragm means belng freely movable.

` 16. Apparatus as defined in claim 15, wherein said n- 'termediate portion of the diaphragm means is substantial- 500,853

ly U-shaped in cross-sectional configuration and said seal- 10 1,03 7,858

ing surface is formed on an annular laterally extending ange portion to thereby define an annular sealing surface.

References Cited in the iile of this patent UNITED STATES PATENTS Dahlke Jan. 27, 1914 FOREIGN PATENTS Great Britain June 28, 1938 Germany Aug. 28, 1958 

1. PUMP SEALING APPARATUS COMPRISING A PUMP HAVING A ROTATABLE MEANS INCLUDING AN IMPELLER, EXHAUST MEANS IN COMMUNICATION WITH ATMOSPHERE, AND SEALING MEANS FOR PREVENTING LIQUID FLOW BETWEEN SAID IMPELLER AND SAID EXHAUST MEANS, SAID SEALING MEANS INCLUDING A FLEXIBLE MOVABLE INTERMEDIATE PORTION, MEANS NORMALLY RETAINING SAID SEALING MEANS IN OPERATIVE SEALING POSITION WITH SAID INTERMEDIATE PORTION IN ENGAGEMENT WITH A PART OF SAID ROTATABLE MEANS, AND SAID PUMP INCLUDING MEANS FOR REDUCING PRESSURE ON THE IMPELLER SIDE OF THE SEALING MEANS BELOW THE PRESSURE ON THE OTHER SIDE OF THE SEALING MEANS TO MOVE SAID SEALING MEANS COMPLETELY OUT OF ENGAGEMENT WITH SAID ROTATABLE MEANS. 